Even though you "know" stuff, using a manual as a check list serves to let you focus in a tense situation and helps to relieve stress. Remember the color coded Terrorist Threat Levels of a few years ago? Military had something similar, except that every level had its accompanying checklist: Threat Level Yellow - do tasks E, F, G and H; Threat Level RED - Insure Lower Level tasks are accomplished and do Tasks J, K, L....... with each task having a detailed list. It beat sitting around wondering just what kind of S was going to hit your personal fan, as happened with the TTLs - warnings without explanations or actions to take.
Besides which, you are only human - you are bound to forget something sooner or later. Hopefully, it won't be something important.
As for myself, I use the Air Force Survival Manual. I'm kind of biased that way. It is sitting next to some other technical manuals which might come in handy should I have to bug out. Nothing classified, or anything like that, just useful information for bare base operations [just how deep should a latrine pit be?]
A word of warning: there is a very thin, fuzzy line between confidence in your abilities and overconfidence. Overconfidence can get you seriously out of the action when you are needed most. Furthermore, you knowing something is all well and good, but what about your wife, or kids, or friends. Having access to the same information - as the military says, training to a common standard - will be vital for your long term comfort or survival.
Just my not so humble opinion,